George Young, the pioneering Australian songwriter and producer of AC/DC, has died at the age of 70.

Young, the brother of AC/DC’s Angus and Malcolm Young, was a member of the Easybeats and co-wrote its classic hit Friday on My Mind.

With his fellow Easybeats member Harry Vanda he became one of Australian pop’s best-known songwriters, creating Yesterday’s Hero and Love Is in the Air for John Paul Young, Evie for Stevie Wright and Hey, St Peter, which he and Vanda recorded as Flash and the Pan, among many others.

The music publishing and recording house Alberts, which had both the Easybeats and AC/DC in its stable, reported Young’s death.

“It is with great sadness that Alberts acknowledge the passing of George Young,” it said. “A consummate songwriter, trailblazing producer, artist, mentor and extraordinary musician, George was above all else a gentleman who was unfailingly modest, charming, intelligent and loyal; a man with a wonderful sense of humour.

“George was a pioneer who, with close friends Harry Vanda and Ted Albert, created a new sound for the Australian music industry.”

It concluded with a message from Harry Vanda, saying: “Rest in Peace my dear friend.”

Jimmy Barnes said on Twitter Young was “a great songwriter, producer and a great human being”.

Young was born in Scotland in 1946 and migrated to Australia with his family as a teenager. The Easybeats formed after Young met the Dutch-born Vanda at the Villawood migrant hostel in Sydney, where both families stayed after arriving in Australia.

After the band broke up in 1969 Vanda and Young embarked on a songwriting career that produced dozens of hits. The pair were inducted into the inaugural Aria hall of fame in 1988, and the Easybeats followed in 2005.